Climate Change Threats to Public Health

Many sectors of society are impacted by accelerating climate change, and public health is no exception. Increasing global temperatures are expanding tropical disease transmission zones. Malaria is now being locally transmitted in the U.S., and in summer 2024, a Massachusetts town closed its parks overnight to prevent the spread of eastern equine encephalitis. Outbreaks of dengue fever, another mosquito-borne disease, were seen in Bangladesh, Puerto Rico, and many Central and South American countries. Several countries, including the U.S., have recently reported their first local transmissions of dengue.

Climate change is leading to the spread of diseases in another way: through more frequent and intense extreme weather events. Droughts and flooding have been largely responsible for the spread of cholera across southern Africa, increasing rain is preventing people in Madagascar from seeking treatment for malaria, and oscillation between extreme flooding from atmospheric rivers and drought is causing a spike in Valley fever in California. Brain health is also being impacted by climate change, with increasing temperatures linked to neurological deterioration.

Planners can prepare for these quickly altering conditions in several ways. Property maintenance codes, improved wastewater management, and other strategies can help reduce the number of mosquito breeding sites and minimize human contact with mosquitoes. Strategies to lessen urban heat island effects, such as increasing green spaces, should be balanced with consideration for how those methods can contribute to mosquito-borne illness transmission. All of these efforts should be conducted in tandem with extensive public outreach and education.